Abstract：
Microplastics (MP) remain contaminants of great concern in the ocean because of their abundance, prevalence, and threat to marine organisms. Still, there is a great need for studies on the impact of MP on marine zooplankton. Here, we investigated the effects of polyethylene terephthalate (PET) microfibers (Mf) on the survival, Mf ingestion and retention, predation, and fecal pellets (FP) of the marine amphipod (Cyphocaris challengeri) at environmentally relevant concentrations (0, 10, 100, 1000, 10,000 and 50,000 Mf·L-1) and varied exposure time (24, 48 and 72 h). Our study demonstrated that exposure of C. challengeri to PET Mf did not affect their survival. The average number of ingested Mf and the Mf ingestion rate increased significantly with Mf concentrations. Nonetheless, the Mf ingestion rates by C. challengeri decreased significantly between 24 and 72 h in the two highest Mf treatments (10,000 and 50,000 Mf·L-1), suggesting careful rejection of the Mf or reduced feeding activity. Indeed, PET Mf significantly reduced the copepod feeding rate of the amphipods at Mf concentrations ≥1000 Mf·L-1 after 24 and 48 h of exposure duration. Over time, prey intake reduction in amphipods due to Mf ingestion could affect their reproductive outcome, growth, development, and cellular and ecosystem function. The encapsulation of PET Mf into the FP of C. challengeri significantly increased the FP density and sinking velocities, ultimately doubling the transfer rate of the FP from the surface waters to the sediments in SoG. Conversely, ingesting PET microfibers and their incorporation in FP will potentially enhance the role of C. challengeri in the biological C pump and sequestration in SoG. Our study showed that changes in Mf concentration had a more significant effect on C. challengeri Mf ingestion and ingestion rate, prey consumption, FP density and sinking velocity than the exposure time.
摘要：
微塑料（MP）由于其丰富而仍然是海洋中备受关注的污染物，患病率,对海洋生物的威胁。尽管如此，有很大的需要研究MP对海洋浮游动物的影响。这里,我们研究了聚对苯二甲酸乙二醇酯（PET）微纤维（Mf）对存活率的影响，Mf摄取和滞留，捕食,和环境相关浓度（0、10、100、1000、10,000和50,000Mf·L-1）和不同暴露时间（24、48和72h）的海洋两栖动物（Cyphocarischalliceri）的粪便颗粒（FP）。我们的研究表明，C.challeneri暴露于PETMf不会影响其生存。随着Mf浓度的增加，Mf的平均摄入数量和Mf摄入速率显着增加。尽管如此，在两种最高Mf处理(10,000和50,000Mf·L-1)中，C.challeneri的Mf摄取率在24至72小时内显着降低，建议小心拒绝Mf或减少进食活动。的确,暴露时间24和48小时后，在Mf浓度≥1000Mf·L-1的情况下，PETMf显着降低了两栖动物的co足类摄食率。随着时间的推移,由于摄入Mf而导致的两栖动物猎物摄入量减少可能会影响其繁殖结果，增长,发展,细胞和生态系统功能。将PETMf封装到C.challeneri的FP中，显着增加了FP密度和下沉速度，最终将FP从地表水到SoG沉积物的传输速率提高了一倍。相反，摄取PET微纤维及其在FP中的掺入将潜在地增强C.challeneri在生物C泵中的作用和在SoG中的隔离。我们的研究表明，Mf浓度的变化对C.chlugeriMf的摄取和摄取速率有更显著的影响，猎物消耗，FP密度和下沉速度比曝光时间长。
